"We rehearsed and he had some meeting out of state, and he showed up on the Air Force One helicopter and I felt weird."

The 'Suit & Tie' hit-maker then mimicked Obama's strut as he left the helicopter.

Timberlake explained: "The camera operators, the producers, everybody who was rehearsing, we all stopped to watch President Obama and he struts off the thing and it was like dead silent, and I looked at everybody and I said, 'Daddy's home'."

Watch Justin Timberlake talk about performing while ill on The Tonight Show with Jay Leno on below: